init commit

.gitignore

+.pio
+.vscode/.browse.c_cpp.db*
+.vscode/c_cpp_properties.json
+.vscode/launch.json
+.vscode/ipch
+.vscode
\ No newline at end of file

include/README

+
+This directory is intended for project header files.
+
+A header file is a file containing C declarations and macro definitions
+to be shared between several project source files. You request the use of a
+header file in your project source file (C, C++, etc) located in `src` folder
+by including it, with the C preprocessing directive `#include'.
+
+```src/main.c
+
+#include "header.h"
+
+int main (void)
+{
+ ...
+}
+```
+
+Including a header file produces the same results as copying the header file
+into each source file that needs it. Such copying would be time-consuming
+and error-prone. With a header file, the related declarations appear
+in only one place. If they need to be changed, they can be changed in one
+place, and programs that include the header file will automatically use the
+new version when next recompiled. The header file eliminates the labor of
+finding and changing all the copies as well as the risk that a failure to
+find one copy will result in inconsistencies within a program.
+
+In C, the usual convention is to give header files names that end with `.h'.
+It is most portable to use only letters, digits, dashes, and underscores in
+header file names, and at most one dot.
+
+Read more about using header files in official GCC documentation:
+
+* Include Syntax
+* Include Operation
+* Once-Only Headers
+* Computed Includes
+
+https://gcc.gnu.org/onlinedocs/cpp/Header-Files.html

lib/README

+
+This directory is intended for project specific (private) libraries.
+PlatformIO will compile them to static libraries and link into executable file.
+
+The source code of each library should be placed in a an own separate directory
+("lib/your_library_name/[here are source files]").
+
+For example, see a structure of the following two libraries `Foo` and `Bar`:
+
+|--lib
+|  |
+|  |--Bar
+|  |  |--docs
+|  |  |--examples
+|  |  |--src
+|  |     |- Bar.c
+|  |     |- Bar.h
+|  |  |- library.json (optional, custom build options, etc) https://docs.platformio.org/page/librarymanager/config.html
+|  |
+|  |--Foo
+|  |  |- Foo.c
+|  |  |- Foo.h
+|  |
+|  |- README --> THIS FILE
+|
+|- platformio.ini
+|--src
+   |- main.c
+
+and a contents of `src/main.c`:
+```
+#include <Foo.h>
+#include <Bar.h>
+
+int main (void)
+{
+  ...
+}
+
+```
+
+PlatformIO Library Dependency Finder will find automatically dependent
+libraries scanning project source files.
+
+More information about PlatformIO Library Dependency Finder
+- https://docs.platformio.org/page/librarymanager/ldf.html

platformio.ini

+; PlatformIO Project Configuration File
+;
+;   Build options: build flags, source filter
+;   Upload options: custom upload port, speed and extra flags
+;   Library options: dependencies, extra library storages
+;   Advanced options: extra scripting
+;
+; Please visit documentation for the other options and examples
+; https://docs.platformio.org/page/projectconf.html
+
+[env:esp32dev]
+platform = espressif32
+board = esp32dev
+framework = arduino
+build_flags = 
+    -DESP32
+upload_port = COM3
+monitor_speed = 115200
+
+[env:AruinoNano]
+platform = atmelavr
+board = nanoatmega328
+framework = arduino
+build_flags = 
+    -DARDUINONANO
+upload_port = COM15
+monitor_speed = 115200
+monitor_port = COM15
+
+[env:STM32]
+build_flags = 
+    -DSTM32
+platform = ststm32
+board = bluepill_f103c8
+framework = arduino
+upload_port = COM16
+upload_protocol = dfu
+board_build.core = maple
+monitor_port = COM16
+monitor_speed = 115200
+
+[env:STM32Stlink]
+build_flags = 
+    -DSTM32
+platform = ststm32
+board = bluepill_f103c8
+framework = arduino
+upload_protocol = stlink
+monitor_port = COM17
+monitor_speed = 115200
+upload_flags = -c set CPUTAPID 0x2ba01477
\ No newline at end of file

src/main.cpp

+#include <Arduino.h>
+
+#define ledLOW LOW
+#define ledHIGH HIGH
+
+#ifdef ESP32
+#define ledPin 2
+#elif ARDUINONANO
+#define ledPin 13
+#elif STM32
+#define ledPin PC13
+#define ledLOW HIGH
+#define ledHIGH LOW
+#endif
+
+double pi(int m)
+{
+  //https://create.arduino.cc/projecthub/colonel/calculating-pi-d85ea7
+  double result = 4;
+  for (int x = 1; x < m; x++)
+  {
+    result *= (2 * x);
+    result /= (2 * x + 1);
+    result *= (2 * x + 2);
+    result /= (2 * x + 1);
+  }
+  return result;
+}
+void setup()
+{
+  // put your setup code here, to run once:
+  pinMode(ledPin, OUTPUT);
+  Serial.begin(115200);
+}
+
+void loop()
+{
+  //put your main code here, to run repeatedly :
+  digitalWrite(ledPin, ledLOW);
+  Serial.println("benchmark started.");
+  auto duration = millis();
+  double total = 0;
+  for (int i = 0; i < 700; i++)
+  {
+    auto result = pi(i);
+    total += result;
+  }
+  Serial.println(total);
+  duration = millis() - duration;
+  Serial.write("finished in ms: ");
+  Serial.println(duration);
+  digitalWrite(ledPin, ledHIGH);
+  while (1)
+  {
+    delay(1000);
+  }
+}
\ No newline at end of file

test/README

+This is a simple floating point computing benchmark for arduino platforms.
+
+It now test 3 boards: ESP32, ArduinoNano and a blue pill.